Grate



G. E. RUTLEDGE ,038,805 v April 28, 1936.

m h h h h I I WV E NToR Patented Apr. 28, 1936 UNITED STATES PATENT OFFICE Application February 23, 1935, Serial No. 7,866 In Canada August 15,1934

4 Claims.

This invention relates particularly to grates used in domestic coal stoves and ranges, although the invention is also of use in furnaces and other larger types of heaters. The ordinary grate bar at present in use is rotatably mounted and has a series of ribs thereon, arranged to give the bar a triangular shape in cross section. This triangular shape of bar has several objections, one of which is that the space between the bars during shaking is considerably increased often allowing a considerable portion of the live fire to fall into the ashpan. Another objection, particularly with anthracite coal, is that the fire is unduly agitated, thus often causing the fire to go out. Still another objection is that clinkers or large pieces of fuel will lodge between the bars when the latter are being shaken, preventing the return of the bars to proper position and rendering it necessary to use a poker to dislodge the ob struction, which usually results in knocking considerable live fuel into the ashpan. Still another objection to the old type of grates is that large flat surfaces are provided on which the ashes lodge, which result in time in preventing the supply of air to the fuel.

My object is to devise a grate in which the spacing between the bars during shaking will remain the same at all times so as to prevent too great a quantity of fuel or ash falling to the ashpan, which will be gentle in its action during shaking so as not to disturb the upper part of the fuel bed, which will be effective in discharging the ash into the ashpan, and which will gradually break up any clinkers or large pieces which may be too large to pass between the bars in the ordinary way.

I attain my object by means of the construction hereinafter described and illustrated in the accompanying drawing in which Fig. 1 is a plan view of the improved grate;

Fig. 2 an end view of the same; and

Fig. 3 a section on the line 3-3 in Fig. 1.

In the drawing like numerals of reference indicate corresponding parts in the difierent figures.

l indicates the grate supporting frame, which may be of any suitable construction, being provided at one end with open top bearings 2 to receive one end of the bars, and at the other end with open side bars 3 to receive the other ends of the bars, to facilitate insertion and removal of the bars.

The bars 4 are of special construction, each having a spiral rib 5 thereon, which is adapted to shave the ashes from the bottom of the fire and work them into the ashpan.

While the spiral rib 5 may be continuous from end to end of the bar, I find that there is a tendenoy, should the bars be rotated continuously 5 in one direction, to pile up the ashes at one place in the pan, and I therefore prefer to provide each bar with a separate spiral rib at each end, working in opposite directions, so that the ashes will be worked to both ends instead of only to one end. 10

It will be evident from the drawing, that the spacing between the bars will be the same at all times, whether the grates are being rocked or not, and therefore there will be no large gaps through which quantities of fuel may fall through 15 or in which obstructions may lodge to interfere with the rocking of the grates.

For the purpose of breaking up any large clinkers, I form in each rib a series of notches 6, the sides of which form shoulders which engage and 20 gradually break up any pieces too large to pass between the grates.

As there is a tendency for grates to warp when overheated, under the weight of fuel I prefer to provide a central support I for the grate bars, 25 which support is secured to or supported on the sides of the frame I and provided on its upper face with open bearings 8 to receive the bars 4, the short unribbed portion 9 between the ribs 5 resting in these bearings. 30

The grate bars 4, as usual, will be provided with the squared ends I 0 for engagement by means of a suitable handle for rocking. the grates.

From the above description it will be seen that I have devised a grate construction which will 35 be free of the objections to the older type bars viz. there is at no time any large space between the bars for quantities of fuel to fall through or for obstructions to lodge to prevent rocking of the bars, that the ashes may be removed with- 9 out unduly agitating the main bed of fuel, and that there are no large areas for ashes to lodge to interfere with the supply of air to the fire.

What I claim as my invention is:- 45

1. A grate bar formed as a revoluble shaft having a worm portion adjacent each end, the pitch of the worm portion at one end of the bar being arranged to operate in the opposite direction to the worm portion of the other end of the bar. 50

2. A grate bar formed as a revoluble shaft having a worm portion adjacent each end, the pitch of the worm portion at one end of the bar being arranged to operate in the opposite direction to the worm portion of the other end of the bar; 55

ing a bearing at opposite ends thereof, a. plurality of grate bars supported in said bearings, each of said bars having a worm portion adjacent each end,- the pitch of the worm portion at one end of the bar being arranged to operate in'the opposite direction to the Worm portion at the other 10 end of the bar.

4. In a grate, the combination of aframe having a bearing at opposite ends thereof, a plurality of grate bars supported in said bearings, each of said bars having a worm portion adjacent each end, the pitch of the worm portion at one end of the bar being arranged to operate in the oppo-.

site direction to the worm portion at the other end of the bar; said worm portions being slight- 1y spaced from one another, and a support extending across the frame on which that portion of each bar between the worm portions rests. GEORGE E. RUTLEDGE. 

